1. Field of the Invention
The present invention relates generally to overhead doors and, more particularly, to a releasable vertical lift overhead door.
2. Description of the Related Art
It is known to provide a sectional overhead door to close an opening in a building such as a warehouse. An example of such an overhead door is disclosed in U.S. Pat. No. 5,720,332 to Nachreiner. This overhead door typically includes a plurality of panels pivotally connected to one another by hinges for extension transversely across the opening. Vertical sides of the panels include roller assemblies for rotational engagement within guide trackways to provide guided movement of the door within the guide trackways from an open position to a closed position.
It is also known that these overhead doors are commonly damaged by material handling equipment, requiring repair or replacement of the door. As a result, it is known to provide a release assembly for an overhead door to release the door from its associated track upon being exposed to a force of a predetermined magnitude. An example of such a release assembly is disclosed in U.S. Pat. No. 5,535,805 to Kellogg et al.
One disadvantage of the above release assembly is that a plunger fits into a track which is undesired. Another disadvantage of the release assembly is that it is provided only on sectional doors. Yet another disadvantage of the release assembly is that it is provided only on doors that are spring counterbalanced and is mounted to a face of the door. Still another disadvantage of the release assembly is that it is cumbersome and complex in its arrangement. A further disadvantage is that the release assembly is relatively costly to manufacture and maintain. Thus, there is a need in the art for a vertical lift overhead door having a release assembly.
It is, therefore, one object of the present invention to provide a new releasable vertical lift overhead door.
It is another object of the present invention to provide a new releasable vertical lift overhead door having either a one leaf or two leaf door.
It is yet another object of the present invention to provide a vertical lift overhead door that releases from its track when exposed to a force of a predetermined magnitude.
To achieve the foregoing objects, the present invention is a releasable vertical lift overhead door. The releasable vertical lift overhead door includes at least one track disposed on each side of an opening of a structure and at least one door leaf disposed between the tracks. The releasable vertical lift overhead door also includes a release assembly attached to the door leaf on each side thereof and having a portion disposed over the track to guide movement of the door leaf along the tracks and to releasably disengage the track when a force of a predetermined magnitude is applied to the door leaf.
One advantage of the present invention is that a new releasable vertical lift overhead door is provided. Another advantage of the present invention is that a releasable vertical lift overhead door is provided having one or two door leafs. Yet another advantage of the present invention is that a vertical lift overhead door is provided with a release assembly on a door leaf that fits over a track and releases from the track when the door leaf is exposed to a force of a predetermined magnitude.
Other objects, features and advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description when taken in conjunction with the accompanying drawings.